Abstract 3073: The Impact of Baseline Mitral Regurgitation on 1-Year Clinical Outcomes in Patients Undergoing Cardiac Resynchronization Therapy

Abstract

Background: The impact of mitral regurgitation (MR) on long-term clinical outcomes in patients (pts) undergoing cardiac resynchronization therapy (CRT) is not well established. Methods: We investigated 110 pts received CRT (age 71+/−10years, NYHA class 3.1+/−0.5, LVEF 26+/−7%, LVEDD 61+/−7mm, pre QRS duration 178+/−29ms) and divided into two groups, 40 pts with baseline MR grade 0 –1 (less MR group) and 70 pts with baseline MR grade 2– 4 (severe MR group). 1-year clinical data were obtained. Results: Baseline clinical and echocardiographic characteristics were similar between two groups without baseline MR grade (0.9+/−0.3 in less MR group vs.2.2+/−0.5 in severe MR group, p<0.0001). At 1-year follow up, NYHA functional class was significantly better in less MR group than severe MR group (1.9+/−0.8 vs.2.4+/−0.6, p=0.0004). Event free survival rate from heart failure hospitalization (HFH) was significantly higher in less MR group compared to severe MR group (93% vs.75% at 1 year, Log-rank p=0.037) and event free survival rate from combined death and HFH was also significantly higher in less MR group (87% vs.69% at 1 year, Log-rank p=0.039). Conclusion: Pts with severe baseline MR had worse clinical outcomes even if received CRT compared to less MR pts.